JP2019110664A - Cooling structure for stator - Google Patents

Abstract

To efficiently cool a stator from the outer circumferential side thereof.SOLUTION: A cooling structure for a stator includes: a stator 16 formed by layering a plurality of laminate plates 30 in the axial direction; a case covering at least a part of the outer circumference of the stator 16; and a refrigerant passage 20 provided between the stator 16 and the case so as to allow a refrigerant to pass therethrough. A plurality of protrusions 32 protruding in the radial direction are provided on the outer circumference of the laminate plates 30. The laminate plates 30 are layered such that positions of the protrusions 32 are deviated from one another in the circumferential direction. As a result, the refrigerant passage 20 has a zigzag passage in the circumferential direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a stator cooling structure for cooling a stator of a rotating electrical machine with a refrigerant.

  In electric vehicles and hybrid vehicles, a motor generator (a rotating electric machine) for driving with a large output is mounted. In such a large output rotary electric machine, the heat generation is also large, and in many cases, it is cooled by the circulating refrigerant. And about cooling of this rotary electric machine, effective cooling is desired and there are various proposals.

  In Patent Document 1, it is shown that, for a stator core formed by laminating laminated plates, an axially penetrating refrigerant passage is formed, and a plurality of projections extending continuously in the axial direction are formed on the wall of the refrigerant passage. It is done.

Japanese Patent Application Publication No. 07-087711

  Here, also for cooling the stator, there are a plurality of means such as forming a refrigerant passage inside the stator and supplying the refrigerant from above. And there is a demand for cooling the stator effectively by any means.

  An object of the present invention is to provide a stator cooling structure capable of effectively cooling the stator from the outer peripheral side thereof.

  According to the present invention, there is provided a stator formed by laminating a plurality of laminated plates in an axial direction, a case covering at least a part of the outer periphery of the stator, and a refrigerant passage provided between the stator and the case for flowing a refrigerant , And a plurality of protruding portions protruding in the radial direction are provided circumferentially at intervals on the outer periphery of the laminated plate, and the laminated plate is stacked while shifting the circumferential position of the protruding portion Thus, the refrigerant passage has a zigzag passage in the circumferential direction.

  In addition, it is preferable that the circumferential length of the projecting portion is shorter than the concave portion existing between the projecting portions, and the projecting portions shifted in adjacent circumferential position are positioned with a gap in the circumferential direction.

  Further, it is preferable that a predetermined number of the laminated plates be used as a block, and the circumferential position of the projecting portion be shifted for each block.

  According to the present invention, since the refrigerant flows through the zigzag refrigerant passage on the outer peripheral side of the stator, the stator can be effectively cooled.

FIG. 2 is a schematic view of a rotating electrical machine as viewed from an axial direction. It is the figure which looked at a part of outer periphery of the stator which concerns on embodiment from the axial direction. It is the figure which looked at a part of outer periphery of the stator which concerns on embodiment from radial direction outer side. BRIEF DESCRIPTION OF THE DRAWINGS It is typical sectional drawing which looked at the rotary electric machine of embodiment from the side. It is a schematic cross section which looked at the rotary electric machine in other embodiments from the side.

  Hereinafter, embodiments of the present invention will be described based on the drawings. The present invention is not limited to the embodiments described herein.

  FIG. 1 is a schematic view of a rotating electrical machine 10 as viewed from an axial direction. At the center is an axially extending rotary shaft 12 around which a cylindrical rotor 14 is secured. In the case of a permanent magnet motor, magnets matched to the number of poles are embedded in the rotor 14.

  A cylindrical stator 16 is provided on the outer side (peripheral side) of the rotor 14. The stator 16 includes a stator core and a stator coil. The stator core has a donut shape, has a plurality of teeth projecting inward, and a plurality of (for example, three-phase) stator coils are wound around the teeth. .

  In addition, the stator core of the stator 16 is formed by laminating a large number of disk-shaped laminated plates. An electromagnetic steel plate etc. are utilized for a lamination plate.

  A case 18 is provided on the outer side (outer periphery side) of the stator 16 at a predetermined interval, and a refrigerant passage 20 is formed between the outer periphery of the stator 16 and the inner wall of the case 18. A refrigerant inlet 20 a is provided at the upper part of the case 18, and a refrigerant outlet 20 b is provided at the lower part of the case 18. If the refrigerant passage 20 flows downward by its own weight, the refrigerant inlet 20a and the refrigerant outlet 20b extend in the axial direction so that the refrigerant flows from the top to the bottom of the entire stator 16 Although it is preferable, as long as the pressure is fed, the refrigerant flowing from one end side in the axial direction as the spiral passage may turn around the outer periphery of the stator 16. In addition, as a refrigerant | coolant, oil, such as ATF (Automatic transmission fluid), is used normally.

  In FIG. 2, the enlarged view which looked at the outer peripheral part of the stator 16 from the axial direction is shown. A projecting portion 32 is formed on the outer peripheral portion of the laminated plate 30 of the stator 16. The protrusion 32 is a portion extending in the radial direction, and can be formed when the outer periphery of the laminated plate 30 is pressed. The circumferential length A of the projecting portion 32 is shorter than the circumferential length B of the recess 34 present between the projecting portions. Therefore, when one lamination plate 30 and the other lamination plate 30 are rotated about the axis to offset their circumferential positions, a gap is generated between the two projecting parts 32.

  The lamination plate 30 is relatively thin. Therefore, in order to form the refrigerant passage 20, it is preferable to use a plurality of laminated plates 30 instead of one laminated plate 30. Therefore, it is preferable to form the refrigerant passage 20 by rotating an angle with respect to the axis by setting a plurality of laminated plates 30 stacked as a set.

  In addition, the protrusion part 32 of the lamination plate 30 can be formed without increasing the number of processes by processing together at the time of punching of the lamination plate 30. FIG.

  In particular, in the formation of the stator core, the lamination plate is rotated at a symmetrical pitch for each predetermined number of blocks, and a rolling process is performed in which the circumferential position with respect to the axis is changed and lamination is performed. It is preferable to offset the circumferential direction position of the protrusion part 32 of the blocks of the lamination | stacking plate 30 by this rolling, and to form a zigzag refrigerant path. For example, if the bolt holes for fixing the laminated plate 30 are every 90 degrees, the positions of the protrusions 32 may be offset every 90 degrees. By this, the position of the protrusion part 32 will differ for every block of rolling, and the refrigerant passage 20 of a zigzag is formed.

  FIG. 3 is a schematic view of the portion of the stator 16 shown in FIG. 2 as viewed from the outside in the radial direction. Therefore, the refrigerant flows in the circumferential direction as shown by the arrow, and in FIG. 3, the circumferential direction is in the vertical direction.

  Thus, in each laminated plate 30, the circumferential position of the projecting portion 32 is offset, so that the position of the projecting portion 32 is shifted between the adjacent laminated plates 30, and there is a gap between the projecting portions 32. Therefore, as shown in the drawing, the refrigerant flowing in the circumferential direction strikes the projecting portion 32 and escapes in the lateral direction to advance in the circumferential direction. By repeating such a thing, a refrigerant will advance zigzag in the direction of an axis, contact of a refrigerant and stator 16 becomes dense, and a cooling effect can be improved.

  FIG. 4 shows a schematic view of a cross section viewed from the side of the rotary electric machine. The rotor 14 is schematically shown in outline. For the stator 16, a plate or block of plates is shown. In addition, the coil end 16 a of the stator coil is shown to project from the axial direction of the stator 16.

  The case 18 is fixed at the periphery of the axial front and rear surfaces of the stator 16. Further, the projecting portion 32 of the laminated plate 30 extends to the inner wall of the case 18, whereby the refrigerant passage 20 is a zigzag passage.

  The case 18 does not have to cover the entire outer periphery of the stator 16 and may be only a part in the axial direction or a part in the circumferential direction.

  FIG. 5 shows the configuration of still another embodiment. In this example, the outer end of the protrusion 32 is located in front of the inner wall of the case 18, and a space through which the refrigerant flows is formed along the inner wall of the case. Therefore, the refrigerant flows even if it passes through the radially outer side of the protrusion 32. However, also in the refrigerant passage 20, the passage of the refrigerant repeats its diameter increasing and decreasing. Therefore, the refrigerant collides with the outer periphery of the stator 16, and the heat exchange efficiency can be increased.

  Thus, according to the cooling structure according to the embodiment, the protrusion 32 provided on the outer periphery of the stator 16 is located in the refrigerant passage 20. As a result, the surface area of the stator 16 in contact with the cooling medium is increased, and the flow of the cooling medium becomes turbulent and the cooling efficiency can be improved. Furthermore, since a circumferential gap is formed between the axially adjacent projecting portions 32, the refrigerant flow in the circumferential direction can be made smooth.

DESCRIPTION OF SYMBOLS 10 rotary electric machines, 12 rotating shafts, 14 rotors, 16 stators, 16a coil ends, 18 cases, 20 refrigerant passages, 20a refrigerant inlets, 20b refrigerant outlets, 30 laminated plates, 32 protrusions, 34 recesses.

Claims (1)

A stator formed by laminating a plurality of laminated plates in the axial direction;
A case covering at least a part of the outer periphery of the stator;
A refrigerant passage provided between the stator and the case for flowing a refrigerant;
Including
On the outer periphery of the laminated plate, a plurality of radially projecting protrusions are provided at intervals in the circumferential direction,
The refrigerant passage has a zigzag passage in the circumferential direction by laminating the laminated plate while shifting the circumferential position of the protrusion.
Stator cooling structure.